Combination of alpha-1 antitrypsin and doxycycline suppresses collagen-induced arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a complex disease characterized by autoimmune inflammation and joint destruction. Despite recent advances in RA treatment, current therapies require further improvement to overcome adverse events and ineffectiveness in some cases. By targeting different pathways/molecules using drug combinations, a better treatment can be obtained, whereas adverse events are reduced. In order to develop a new treatment option, the present study employs a gene therapy-based combination therapy using doxycycline and human alpha-1 antitrypsin (hAAT). METHODS: DBA/1 mice were immunized with type II collagen to induce arthritis. Four weeks before immunization, they received a doxycycline containing diet and a single injection of adeno-associated virus vector expressing hAAT under the control of a tetracycline-dependent promoter. Control groups received doxycycline alone or saline. Macroscopic arthritis development as well as histopathological changes in the joint were evaluated. In addition, the effects of hAAT and doxycycline on lipopolysaccharide (LPS)- or tumor necrosis factor-alpha-induced interleukin (IL)-6 production from mouse fibroblast cells were also determined. RESULTS: Combination therapy significantly reduced arthritis development and progression compared to the control group in respect to macroscopic as well as histopathological changes. Doxycycline and hAAT in combination also inhibited IL-6 expression from LPS-stimulated NIH/3T3 mouse fibroblast cells, indicating a contributing mechanism of arthritis inhibition. CONCLUSIONS: The results obtained in the present study indicate that a combination therapy using AAT and doxycycline holds promising potential as a new therapy for RA.

Inhibition of proteasome by bortezomib causes intracellular aggregation of hepatic serpins and increases the latent circulating form of antithrombin.

Conformational diseases include heterogeneous disorders sharing a similar pathological mechanism, leading to intracellular aggregation of proteins with toxic effects. Serpins are commonly involved in these diseases. These are structurally sensitive molecules that modify their folding under even minor genetic or environmental variations. Indeed, under normal conditions, the rate of misfolding of serpins is high and unfolded serpins must be degraded by the proteasome system. Our aim was to study the effects of bortezomib, a proteasome inhibitor, on conformationally sensitive serpins. The effects of bortezomib were analysed in patients with multiple myeloma, HepG2 cells, and Swiss mice, as well as in vitro. Levels, anti-FXa activity, heparin affinity, and conformational features of antithrombin, a relevant anticoagulant serpin, were analysed. Histological, ultrastructural features and immunohistological distribution of antithrombin and alpha1-antitrypsin (another hepatic serpin) were evaluated. We also studied the intracellular accumulation of conformationally sensitive (fibrinogen) or non-sensitive (prothrombin) hepatic proteins. The inhibition of the proteasome caused intracellular accumulation and aggregation of serpins within the endoplasmic reticulum that was associated with confronting cisternae and Mallory body formation. These effects were accompanied by a heat stress response. Bortezomib also increased the levels of intracellular fibrinogen, but has no significant effect on prothrombin. Finally, bortezomib had only minor effects on the mature circulating antithrombin, with increased amounts of latent antithrombin in plasma. These results suggest that the impairment of proteasomal activities leads to an intracellular accumulation of conformationally sensitive proteins and might facilitate the release of misfolded serpins into circulation where they adopt more stable conformations.

Autoantibodies to cryptic epitopes of C-reactive protein and other acute phase proteins in the toxic oil syndrome.

Toxic oil syndrome (TOS) was caused by the consumption of rapeseed oil contaminated with derivatives of aniline. Many persons who survived the acute phase developed a puzzling, multi-year chronic disease considered to be inflammatory or autoimmune in nature. In attempting to characterize their autoantibodies, we found that 74% of TOS patients with chronic disease had IgG antibodies to C-reactive protein (CRP). This activity was detectable only when CRP was chemically or physically denatured and behaved like a previously described antibody produced by immunization with the CRP monomer. Significant antibody reactivities to other acute phase proteins, especially alpha 1-antitrypsin and fibrinogen (P < 0.025) and ceruloplasmin (P < 0.05) were also observed. IgG antibodies to cryptic epitopes in CRP and other major serum proteins that increase during the acute phase response may reflect an earlier toxin-mediated insult to the liver that included abnormal biosynthesis of and/or damage to acute phase proteins.

Acute phase proteins, humoral and cell mediated immunity in environmentally-induced hyperthermia in man.

The effects of repeated hyperthermia, caused by a Finnish sauna bath over 1 week, on the serum levels of some acute phase reactant proteins and on both humoral and cell-mediated immunity on twelve healthy young volunteers are presented. The mean rise in rectal temperature during each 30-min period in the bath was about 1.3 degrees C. Heat exposure caused significant increases in the serum concentrations of two of the acute phase reactant proteins, alpha1-antitrypsin (from a mean value of 1.8 (0.1) to 1.9 (0.2) g X l-1, p less than 0.01) and transferrin (from a mean value of 36.9 (3.4) to 38.3 (4.4) mumol X l-1, p less than 0.05), but no changes occurred in immunoglobulins or cell-mediated immunity. These findings suggest that environmentally induced hyperthermia can initiate the acute phase reaction associated with fever.